Control valve devices



' P 3, 1957 w. E. voss CONTROL VALVE mzvxcss Filed March 10. 1955'United States Patent 9 i CONTROL VALVE DEVICES Waldemar Emil Voss,Kenton, England, assignor to Adams Limited, London, England, a BritishCompany Application March 10, 1955, Serial No. 493,403 Claims priority,application Great Britain April 9, 1954 8 Claims. (Cl. 251-214) Thisinvention relates to control valve devices for use in pressure fluidsystems, more especially for use in conjunction with compressed gaseousoxygen supply systems, such as are used in respiration aids in aviation,mountaineering and surgery, and has for an object the provision of valvedevices having improved ease of operation, reduction in weight,elimination of added lubricant, extended life and increased resistanceto wear and improved sealing both in the fully open and closed positionsand in all intermediate positions, in particular when both the inlet andoutlet connections of the valve device are connected to a system at apressure greater than atmospheric pressure.

According to the persent invention, a valve device includes a valvebody,bored to provide an inlet and an outlet port, a valve element having anoperating spindle and a hemispherical nose adapted to seat on a conicalseat insaid bore to seal the outlet port, a tapered gland member, suchas a. bushing, accommodating or receiving said spindle for co-operationwith a second conical seating surface formed in a thrust member, such asa block in the valve body, to provide a leak-proof joint between thevalve spindle and valve body.

The tapered gland member or bushing is preferably bored and formedinternally with a female thread to engage a male thread on the valvespindle, the tapering of the gland bushing providing diminishingthickness, so as to' form a resilient gland seal concentric with andsurrounding the spindle.

The gland bushing is preferably continuously maintained in close contactwith the spindle by spring loadingthe thrust block, which is formed witha tapered bore, so as to be located in line contact around the taperinggland bushing and to compress said bushing inwardly to grip the valvespindle under pressure exerted by the spring through the thrust block.To assist in this, the lower end of the gland bushing terminates in arounded flange.

Preferably the gland bushing is formed as a freely fitting sleeve insertin the valve body, and is locked against rotation and sealed to saidbody, adjacent the top thereof, through an integral flange compressedonto a seating surface in the valve body, by means of a clamping nutscrewing onto thevalve body and concentric with the valve spindle.

Preferably the valve body is made of a light metal or light metal alloy,for example aluminium or aluminium alloy, whilst the gland member ispreferably made from a slightly resilient synthetic material such asnylon, which requires no lubricant for the mating screw thread of thevalve spindle and which will maintain a gland seal around the spindlewithout increasing the operating torque excessively.

The thrust block is preferably made of harder material than the gland,such as aluminium-alloy, and is relatively non-resilient. -In order tominimise wear between the valve seat and valve element nose, one of thetwo is preferably made of 2,805,040 Patented Sept. 3, 1957 ice Thethrust block is conveniently spring loaded against.

the rounded flange of the gland bushing surrounding the valve spindle bymeans of a compression spring fitted in a recess in the valve body andconcentric with the valve spindle.

One form of valve device according to this invention for use incontrolling flow of compressed gaseous oxygen, is illustrated invertical section in the accompanying drawing, referring to which thereis provided a valve body 1 of aluminium or aluminium alloy, which isbored centrally as at 2, and has two further bores forming passages atright angles to the main bore 2, one of said secondary bores forming aninlet port or passage 3, and the other an outlet port or passage 4.Where the inlet passage 3 communicates with the central bore 2, the body1 is formed with a conical seat 5, with which the valve element isadapted to co-operate. Said valve element comprises a valve spindle 6 ofstainless steel, terminating in a hemspherical nose 7, preferably formedof polished in the top surface of the valve body by a clamping nut 11,e. g. of a light alloy, which screws onto a thread 12 on the outerdiameter of the valve body and secured by a lock nut 13.

The nylon gland bushing 9 is bored out to receive a.

female thread for engagement by the thread 8 on the valve spindle 6,whilst the lower end of the bushing is tapered as at 14 and terminatesin a rounded flange 15, the whole gland bushing element including thetapered portion 14, flange 15, threaded bore and flange 10 forming onecomponent.

The top of the screw thread on the valve spindle 6 is protected by astainless steel washer 16 which forms a stop for the valve spindle inthe fully open position against the lower surface of the clamping nut11.

A thrust block 17, e. g. of hard aluminium or aluminium alloy, isprovided as a free fit within the main bore 2 of the valve body 1 and isformed with an internal tapered bore, such as to provide free locationof the thrust block on the rounded flange 15 of the nylon gland bushing9, with a line contact between said block and flange, thereby giving anequal closing pressure all round the gland bushing onto the valvespindle. At the lower'end, the

tapered bore of the thrust block is clear of the valve.

spindle, which passes through it.

The thrust block 17 is at all times maintained in pressure contact withthe rounded flange 15 of the nylon gland bushing 9 by a compressionspring 18, which presses the thrust block 17 upwards and tends therebyto compress the said flange and tapering wall of the nylongland-bujshvalverspindleinose, 7,1Ito thekoutlettpassaget' arid;port .4.Reverselotatinn ot,tthel lcnobswilhl of course reseat then valveandsealthe-inletL, I l

In all positions of the valve spindleironrlthe closedl.

position.( as .shown when,theqspindletnose 'l is screwed 10 into contactwithatheaseat 15,10 the fully, open positionwhenthe washer v.lficomesintocontact withrthe lower surface oftthehclarnpinggnut 11," thereby,preventing furtheri counterclockwise. rotation. of: the knpbandi valvespindle;

by the tapered nylon gland bushing which is compressed around, thewalve: spindle, by pressure-from the compression -spring;,18:applied-wthrough} the Jathl'ust: block :17.

Whenthe. spindle KIIOSGQTIIS screwed homevonto itsseat 5,; the?reaction: between: the imale: screw thread 8 of the;:valv,e spindle=6and itszmatinggfemalezthreaddn the nylonglandbushingiQ-willnormallyaztendto lift the lower endaof the nylon{gland bushing :upwards .tfroms contact with the thrust: block 115;;This :tendencyis overcorne-by thecomprlessionsspring 18- whichtmakesgoodthe reaction l y xpanding; tcr maintain. the lthrustvbleckr in contactwith-itherounde'drflan-ge 15 .ofithenylon gland bushing 95 Inthe fully,openiposition, when:- the :wash'er 16 'abutsthe undensurfaceoftheclamping: nut 11 andthe reaction.be-- 3 tween theivalve;spindlesdzandanylon gland bushing screw 1 threads rsiinatheiopposite direction, the sealing ofthe valve spindle :is assisted byslight additional compressionof? thezspringztransmitted: by downwardmovement of the 7 lower end of the nylon gland bushing into the thrustblock; In :known;valves :ofthe needle type; the Naive-spindlenose-andfseat are tCOHlHlOIllY both of=metal, one of-wl1ich tends :ttoiindentas progressively larger forces are employedin attempting to seal-by screwing the valve spindle down, with increasing-torques, whichaggravate deforma- 7 tion either ofthe :seat or spindle-nose,resultingin leakage and -inability 'tdseal. -It willbe appreciated thatin valves according to this invention, theme 'of' slightly resilientsynthetic material such as unplasticized acrylic resin=for the spindlenose seating ina'coned metal seat permits-a-seal to be-achievedwithoutpermanent deformationz'and Wea-r ofeither component, and Withoutexcessive torqueeappliedto lheIVBlVE spindle? It "willalso'be'appreciated that, whereas in known needle type" valves, inparticular invalves employed in compressed gaseous oxygen systems thevalve body is commonly made) of brass r or bronze, female screwthreadedto. accept the malescrewed steel valve spindle, so' that operation. ispossible without seizure, since nor- InaLlubrication cannottbe appliedin contactwith compressed oxygenrowing to the risk of fire or explosion,

the use ,of anylontgland bushing invalves according to this invention,female screw-threaded to: receive the male screwthread of the-valvespindle, not only permits easy rotation of the. valve spindle:withouthlbricant, but also allows the valve body to .bemadein aluminiumor aluminium alloy with. considerable-economy in -weight, which isa-vital consideration-in aircraft or portable--applications. 7

f Again, -in"known 'needletypej valves, sealing of the valvespindlejiscommonly attempted by meansof compressedorganic material, suchas leather, or by asbestos, surrounding the valve spindle andcompressedraroundit b'y'a gland'nut at the point where the valve spindleleaves the valve body, that is at the endremote from the valve seat.Not; only isthis conducive to leakage pastthe stem; especially whenpressure ygreatenthan atmospheric pressure exists'at both ports of the,valve,,but also the gland nut requires to be tightened progressively inan attempt to maintain the seal as the gland material becomes compressedandinela'stic'.

In valves according to this'invention, the valve spindle is eflfectivelysealed near the lower end adjacent to the spindle nose and valve seat bymeans of the tapered and rounded lower end of thergland bushing, thrustblock and compression spring combination, and the function of theclamping ;nut is .gto;:clamp;the ,I61SilL6nb-ffi3l1g6 of the nylon glandbushing to the toppf the valve body and to act as amp-in':the1-fully-*open tppsitionfofithe' valve:

V The spindle seal thus produceddo'es not increase operating torque-sonthe spindle--excessively,; ina,view of thetlow-frictionalcharacteristics between the spindle and nylon, .and is also resistant*to' wear;"slightdimensional" changes "he ewthreadg leakagespaststhervalve spindlegisg-prevented ing taken up bygthesspringgloading ofjthecompression spring exerted through the thrust block. Sealing at thelower end of the valve spindle assists freedom from leakage:whenapressure \greatentthan atmosplrenicisincident lat the outletportpeveruwhen :the:.valve 1is;:closed,; and alsoe reducesttheoperatingstorque inzcornparisonmith:'valvesiof L7 similanr type: whereathe:.-spindlez.-isi sealedeanithe 'end ire lIlOtB'i from tthe:seat=;by: restrieting;the.:areaaofit spindle cross: section; exposed-ztoiatheiipwardiaforce of1the -fiuid i pressures-supply;eifectively;itoizt'ha'teofi :the= va1ve spindle i tipwhiehzis small: in :compar-isQnwithithat of :the screwthreadechipo'rtion; ithel pressnresloadron the:valve spindle screwithreadsdsthereforenninimisedc Finally such valvesare :abletto :functionzawithi the zsameeificiencys at high on:lowetemperaturesi ofg-e; g. 6095-16. and -40 CL, e tropical or arctictemperatures, since it is so formed asdo. allowrautomatically ,forexpansione'and contraction of the material under this range oftemperatures;

What is claimediis: 2- 7 7 1. A control lvalvedevicezcomprising a valve'body hav ingiarmainshoreatherein andinletlandloutlet ports =incommunicati'or uwithasaidt main -.bore; ayvalves elementpositioned-ainisaidomaincborelandi'terminating at one end -in ahemisphericalrnosepa male-threaded operatinglspindl'e': connected-tothe: other; end; ofz'saidzvalverelementn and: extending through one endoftsaidemaincbore thetether endof said .m aim rbore havingxalconicaleseating surface 0n-WhiChlthei hemispherical nose 1' of;saidwalve; element may seattto seal said-ioutlet passage;aminternallybored-i tapered. .glandl member of. diminishinggythickness post-.3tionedin said mainebore and receivingasaid operatingi spindle, saidgland member havingsthreadsetoraengages the. threads ;on::said;spindle;,and an annular thrust member--concentricallyspositioned inzsaidmainboreiandrhav-i ing-1a conical seating -.'surface: in. whichtherdiminished; thickness end ofsaidtaperedv glandgmember. seats doprov-t vide a lleakiproof joint between: said: valve-gspindle 5 and thewall. of saidrrnain bore;

2. A control valve; device as;claimed.in:claim: l include; ing springmeans;,interp osed between :said none; endiof: said main borer andsaidthrust: members ,andxreaefing against: theilatter, so 7 as. to,cause-,the:;conical sseatingzasuri face, ofsaid thrust member tocgripg:saidtdiminishedzthickaz ness, end; of= said gland member and press. it:against said; spindle. 1 V t 3. A control valve devicei as claimed,1in=clail;;2 in: which the gland member is formed at itsdiminishedz-thickw ness: end with aroundedflange, v

4. A control valvev device as claimed; in claim 17in? which ,the gland,member is formed 1 as a; freelyafitting; sleevevinsertfin the valvebody,-,,and.islocked. against; rotation and sealed vto said ,body,adjacent the top there; of, through. an integral flange compressedonto,aiseatingsurface on. the :valve body by means of a clamping nnt:screwing onto the valve body and concentric with-thevalve spindle- 5.-A: control valver device as claimed inclaim-13; in:- which the glandmember is formed as a freely fitting, sleeve insert-inthe valve body,and-is locked against rotation, andsealed. to said ,body,adjacentthe-wplhereof, through an integral flange compressed onto aseating 5 surface on the valve body, by means of a clamping nut screwingonto the valve body and concentric with the valve spindle.

6. A control valve device as claimed in claim 1 in which the valve bodyis made of a light metal whilst the gland member is made from a slightlyresilient synthetic material, such for example as nylon.

7. A control valve device as claimed in claim 6 in which the thrustmember is made of harder material than the gland member and isrelatively non-resilient.

8. A control valve device as claimed in claim 7 in which the nose of thevalve element is formed of an unplasticized acrylic resin, the valveseat being formed in the metal valve body with a concave truncatedconical contour.

6 References Cited in the file of this patent UNITED STATES PATENTSSauer Oct. 5, Holtz July 26, Hackathorn Feb. 14, Tucci July 21,

FOREIGN PATENTS Great Britain of Great Britain of Italy of

